JP2003005014A - Actuator for optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator for an optical element which can drive the optical element with high sensitivity in two directions, namely, a 1st and 2nd that are natually orthogonal directions. SOLUTION: The actuator holds the optical element so that the optical element can be driven in the two orthogonal focusing direction X and tracking direction Y and is equipped with a holder 110 which holds a lens 100, two 1st fitting surfaces 111a and 111b and two 2nd fitting surfaces 112a and 112b provided on the holder 110 while surrounding the center axis O1 of the holder 110, flat focusing coils 131 and 132 which are fitted in parallel to the 1st fitting surfaces 111a and 111b, flat tracking coils 133 and 134 which are fitted in parallel to the 2nd fitting surfaces 112a and 112b, magnets 151 and 152, and 153 and 154 which apply magnetic fields to those coils 131 and 132, and 133 and 134, and springs 140a and 140b which support the holder 110 so that the holder can be driven in the focusing direction X and tracking direction Y.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to recording and / or reproducing information on an optical recording medium such as a magneto-optical disk drive, a write-once disk drive, a phase change disk drive, a CD-ROM, a DVD and an optical card. The present invention relates to an actuator that drivably supports an optical element such as an objective lens used in an information recording / reproducing apparatus, a coupling lens for an optical fiber used in optical communication, or an objective lens of a scanning microscope.

[0002]

2. Description of the Related Art For example, in an optical pickup actuator used in an optical device such as the above information recording / reproducing device, an objective lens which is an optical element is supported so as to be drivable in two directions of a focus direction and a tracking direction which are orthogonal to each other, It is necessary to accurately position the light spot of the lens on the recording track of the recording medium. Therefore, as an actuator that supports the optical element so that it can be driven in two directions,
Conventionally, various types having high driving sensitivity have been proposed for the purpose of improving recording density and access speed.

For example, an actuator as shown in FIG. 7 is proposed in Japanese Utility Model Laid-Open No. 2-30120 (hereinafter referred to as "prior art 1"). This actuator holds the objective lens 10 with a holder 11 and adjusts the focus direction X.
And the flat focus coil 12 and the tracking coil 1 on the two mounting surfaces 11f (only one is shown in FIG. 7) facing the holder 11 in the tangential direction Z orthogonal to the tracking direction Y, respectively.
3 are arranged one by one, and an effective magnetic field is directed to the focus coil 12 and the tracking coil 13 from the magnet 14 arranged to face each other through the yoke 15. This conventional technique is based on the focus coil 1
In FIG. 2, the two sides of the working sides 12a and 12b are used as effective sides, and in the tracking coil 13, the working side 1 is used.
The responsiveness (driving sensitivity) of the actuator is enhanced by utilizing the two sides of 3a and 13b as effective sides where electromagnetic force is generated.

Further, Japanese Patent No. 2620221 (hereinafter, referred to as
Prior art 2) proposes an actuator as shown in FIG. In order to efficiently generate a driving force in the tracking direction, this actuator winds a focus coil 22 around the outer periphery of a holder 21 that holds the objective lens 20 and also attaches a tracking coil 23 to one side surface of the holder 21. 22 and the tracking coil 23 from the magnets 24a and 24b arranged to face each other to the outer yoke 25.
The effective magnetic field is directed through a and the inner yoke 25b.

[0005]

However, it has been clarified that such an actuator according to the prior art has the following disadvantages.

First, in the actuator as shown in the prior art 1, since the focus coil 12 and the tracking coil 13 are integrally attached to the attachment surface 11f arranged in the tangential direction, the focus coil 12 and the tracking coil are attached. There is a limit to the increase in size of No. 13, and it was difficult to increase the driving sensitivity.

Further, in the actuator as shown in the prior art 2, since the tracking coil 23 is attached to the holder 21 around which the focus coil 22 is wound, the focus coil 22 has three magnets 24a, 2a.
Only the two magnets 24a of 4b act on the focus coil 22 of the portion to which the tracking coil 23 is attached (the portion extending along the tracking direction Y).
Wasted and it was difficult to increase the driving sensitivity.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to drive an optical element with high sensitivity in two directions, ie, a first direction and a second direction which are orthogonal to each other. It is an object to provide an actuator for a device.

[0009]

Therefore, an actuator for an optical element according to a first aspect of the present invention is an actuator for an optical element that drivably supports an optical element in two directions orthogonal to each other, a first direction and a second direction. A holder for holding the optical element, two first mounting surfaces and two second mounting surfaces provided on the holder so as to surround the central axis of the holder, and mounted in parallel to the first mounting surface. The first flat coil, the second flat coil mounted parallel to the second mounting surface, the magnetic field generating means for directing a magnetic field to the first and second flat coils, and the holder being the first. And a support member that is supported so as to be drivable in the second direction and the second direction.

An actuator for an optical element according to a second aspect of the present invention is an actuator for an optical element that drivably supports the optical element in two directions, ie, a first direction and a second direction orthogonal to each other, and a holder for holding the optical element. , Two first mounting surfaces arranged to face the holder in the second direction, and two second mounting surfaces arranged to face the holder in a third direction orthogonal to the first and second directions, A first flat coil mounted parallel to the first mounting surface, a second flat coil mounted parallel to the second mounting surface, and a magnetic field applied to the first and second flat coils. It is characterized in that it is provided with a magnetic field generating means for directing and a supporting member for supporting the holder so as to be drivable in the first direction and the second direction.

In a third aspect based on the first or second aspect, it is preferable that the magnetic field generating means is a two-pole magnetized magnet.

[0012] In a fourth invention according to the second or third invention, the first flat coil generates a driving force in a first direction, and the second flat coil has a driving force in a second direction. Is preferably generated.

In a fifth aspect based on any one of the first to fourth aspects, it is preferable that the magnetic field generating means is an open magnetic circuit having no yoke forming a magnetic gap.

In a sixth aspect based on any one of the second to fifth aspects, it is preferable that the support member sandwiches the first flat coil.

In a seventh aspect based on any one of the second to sixth aspects, it is preferable that the first direction is a direction parallel to the optical axis of the optical element.

In an eighth aspect based on any one of the second to seventh aspects, at least one of the first flat coil and the first flat coil can control a direction of a current flowing through the coil. It is preferable that it is

Furthermore, an actuator for an optical element according to a ninth aspect of the present invention is an actuator for an optical element that supports an optical element so as to be drivable in two directions, ie, a first direction and a second direction which are orthogonal to each other. , The second
Direction, two first mounting surfaces that are arranged to face the holder, two second mounting surfaces that are arranged to face the holder in a third direction orthogonal to the first and second directions, and the first mounting A first magnet mounted parallel to a surface, a second magnet mounted parallel to the second mounting surface, and a coil arranged to face the first and second magnets; And a support member that supports the holder so as to be drivable in the first direction and the second direction.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 3 are perspective views showing a recording / reproducing apparatus for an optical disc according to a first embodiment of the present invention, respectively.
FIG. 2 is a top view of FIG. 1, a cross-sectional view showing FIG. 1 from the tangential direction, and FIG. 4 shows an exploded view thereof.

This recording / reproducing apparatus is a recording / reproducing apparatus for the optical disk 1 (see FIG. 3) of the phase change recording system, and has a first direction (focus direction) X and a second direction orthogonal to the objective lens 100 which is an optical element. Direction (tracking direction) Y
Is supported so that it can be driven in two directions. As the optical disk 1, an existing optical disk whose recording surface 1f is covered with a thin cover glass 1c of 0-0.1 (mm) is used.

As shown in FIGS. 3 and 4, the objective lens 100 has a high NA of 0.7 to 0.9, and the upper end of the holder 110 whose central axis O ₁ coincides with the optical axis of the objective lens 100. It is fixedly held in the mounting hole formed in. The holder 110 also fixedly holds the chromatic aberration correction lens 120 at its lower end, and the chromatic aberration correction lens 120
While functioning as a balancer in the focus direction X of the objective lens 100, the objective lens 100 functions as a balancer in the focus direction X of the chromatic aberration correction lens 120. In this case, the holder 110 does not need an extra balancer.

As shown in FIG. 4, the holder 110 includes two first mounting surfaces 111a and 111b arranged to face the holder 110 in the tracking direction Y, and a third direction (which is orthogonal to the focus direction X and the tracking direction Y). Two second mounting surfaces 112a, 112 arranged to face the holder 110 in the tangential direction) Z.
b and.

The first mounting surface 111a has two projections protruding along the tracking direction Y, and these projections position the first flat coil (hereinafter referred to as focus coil) 131 on the first mounting surface 111a. In this state, the first attachment surface 111a is bonded and fixed in parallel to the entire surface of the first attachment surface 111a. The first mounting surface 111b
Similarly, two projections (not shown) protruding along the tracking direction Y are formed, and these projections form a first flat coil (hereinafter referred to as a focus coil).
In a state in which 132 is positioned on the first mounting surface 111b, it is bonded and fixed in parallel to the entire surface of the first mounting surface 111b.

Further, the second mounting surface 112a has two protrusions protruding along the tangential direction Z, and the second flat coil (hereinafter referred to as tracking coil) 133 is attached to the second mounting surface 112a by these protrusions. In the positioned state, it is adhesively fixed in parallel to the entire surface of the second mounting surface 112a. Similarly, the second mounting surface 112b also has two protrusions (not shown) protruding along the tangential direction Z, and these second protrusions cause the second flat coil (hereinafter referred to as tracking coil) 134 to move to the first position. While being positioned on the second mounting surface 112b, the second mounting surface 112b is bonded and fixed in parallel to the entire surface of the second mounting surface 112b.

That is, the focus coils 131 and 132
The tracking coils 133 and 134 are provided so as to surround the central axis O _{1 of the} holder, that is, the optical axis of the objective lens 100, and to be opposed to each other in total of four.
First mounting surface 111 parallel to two focus directions X
a, 111b and second mounting surfaces 112a, 112b
Mounted parallel to.

Further, the holder 110 is integrally provided with two fixing portions 115 extending along the focus direction X at two positions on the tracking coil 133 side, and one ends of springs 140a and 140b are bonded to the fixing portions 115, respectively. It is fixed. The springs 140a and 140b have a thickness of 0.05 (m
A thin plate made of beryllium copper of about m) is edging processed, and the middle portion of the springs 140a and 140b is
A base 1 surrounding the objective lens 100 and described later.
It is located so as to sandwich the focus coils 131 and 132 together with 41. Then, the other ends of the springs 140a and 140b are respectively attached to the upper and lower ends of the spring holder 142.
Each of them is adhesively fixed to spring fixing portions 142a and 142b formed integrally with the spring holder 142.

The spring holder 142 is attached to the base 14 by two bosses formed on its mounting surface 142f.
It is adhesively fixed in a state in which it is positioned with respect to the first mounting surface 141g.

The base 141 has a substantially cylindrical shape formed by drawing an iron plate having a thickness of 0.6 (mm), and its inner walls facing each other in the tracking direction Y are magnetized in two poles in the focusing direction X. Focus magnet 151,1
While the 52 is bonded, the tracking direction Y
Tracking magnets 153 and 15 with two poles
Bond 4 together. In this case, it is convenient to use a two-pole magnetized magnet as the magnetic field generating means because it is possible to easily generate a magnetic field of a required magnitude.

That is, the focus magnet 151
The magnetic pole of (152) is the focus coil 131 (13
The magnetic pole of the tracking magnet 153 (154) extends in the focus direction X of the tracking coil 133 (134), facing the two action sides 131a and 131b (132a and 132b) extending in the tangential direction Z of 2). Two working sides 133a and 133
b (134a and 134b).

As shown in FIG. 3, the base 141 is integrally formed with a spherical surface portion 141f for adjusting the inclination at the lower end thereof. The spherical surface portion 141f is opposed to the conical surface 160f formed on the upper surface of the carriage 160. Abut and tilt. As a result, the base 141 is adjusted in inclination with respect to the carriage 160, and then is adhesively fixed to the carriage 160. A reflection mirror 161 is housed in the conical surface 160f of the carriage 160, as shown in FIG.

Further, the sensor holder 162 is fixed to the outer surface of the base 141 in the tracking direction Y. The sensor holder 162 includes a PD (photodiode) 163 and an LED (light emitting diode) 164 having light-receiving surfaces divided in two in the tracking direction Y, at both ends facing each other in the tangential direction Z.

The light emitted from the LED 164 is stored in the holder 1
PD1 is projected on the light-shielding bar 116 arranged at the lower end of 10.
It is incident on the light receiving unit 63. At this time, the objective lens 10
When the holder 110 moves in the tracking direction Y integrally with 0, the light-shielding bar 116 also moves in the tracking direction Y. Therefore, the output difference between the two light-receiving surfaces on the PD 163 is calculated to obtain the tracking direction of the objective lens 100. The position at Y can be detected.

The light emitted from the LED 164 is arranged so as to be orthogonal to and intersect with the light incident on the reflection mirror 161 from the laser. As a result, the space can be effectively used and the recording / reproducing apparatus can be downsized.

The recording / reproducing apparatus of this embodiment, as shown in FIG. 3, reflects light from a laser (not shown) into a reflection mirror 161.
Then, the reflected light is incident on the objective lens 100 through the chromatic aberration correction lens 120 to form a light spot on the recording surface 1f of the optical disc 1. Further, in the present embodiment, the reflected light from the recording surface 1f of the optical disc 1 is made to follow the reverse optical path to the objective lens 100, the chromatic aberration correction lens 120, and the reflection mirror 161, and is incident on the light receiving element via the error detection optical element. By doing so, tracking error detection, focus error detection, and RF signal detection can be performed. Since various types of such optical systems have been proposed, description thereof will be omitted.

Here, a method of finely adjusting the objective lens 100 will be described.

First, when the objective lens 100 is finely adjusted in the focus direction X, the focus coils 131 and 13 are used.
Power is supplied to 2 via springs 140a and 140b. At this time, the two working sides 131a of the focus coil 131,
The same force cooperating with the magnetic fields from the focus magnets 151 and 152 is generated along the focus direction X on the two action sides 132a and 132b of the 131b and the focus coil 132, respectively, so that the holder 110 moves in the focus direction X. By driving along, the objective lens 100 can be finely adjusted in the focus direction X.

Next, when finely adjusting the objective lens 100 in the tracking direction Y, the tracking coil 133,
Power is supplied to 134 via springs 140a and 140b. At this time, the working side 133a of the tracking coil 133,
133b and working edge 13 of tracking coil 134
Since the same force cooperating with the magnetic fields from the tracking magnets 153 and 154 is generated along the tracking direction Y in each of 4a and 134b, the holder 110 is driven along the tracking direction Y and the objective lens 100 is driven.
Can be finely adjusted in the tracking direction Y.

In this embodiment, the central axis O _{1 of the} holder 110 is
The first mounting surfaces 111a and 111b provided on the holder 110 so as to surround the optical axis of the objective lens 100 that coincides with
And the second mounting surfaces 112a and 112b,
The flat focus coils 131 and 132 and the tracking coils 133 and 134 are respectively attached to the first attachment surfaces 111a and 111b and the second attachment surface 112a,
Focus coil 1 mounted parallel to 112b
31, 132 and tracking coils 133, 134
Focus magnets 151 and 152 and tracking magnet 1 as magnetic field generating means for directing a magnetic field to
Since 53 and 154 are made to correspond respectively, the first mounting surface 111a, 111b and the second mounting surface 112a,
In 112b, a sufficient arrangement space for the focus coils 131, 132 and the tracking coils 133, 134 can be secured.

Further, by disposing the driving coils 131 to 134 on substantially the entire outer peripheral surface surrounding the central axis O ₁ of the holder 110, the useless empty space around the holder 110 can be minimized and used efficiently. is doing. Further, the focus driving coils 131 and 132 and the magnets 151 and 152, and the tracking driving coils 133 and 134 and the magnets 153 and 154 are not arranged on the same plane, but separate mounting surfaces 111a and 111b which are perpendicular to each other. , 112a, 112b, a large coil and a magnet can be arranged in each.

Therefore, according to the present embodiment, the focus coils 131, 132 and the tracking coil 133,
Since 134 can be set to have a large outer dimension, the respective working sides 131a, 131b, 132
a, 132b, 133a, 133b, 134a, 134
Since the length and volume of b can be increased, and the focus magnets 151 and 152 and the tracking magnets 153 and 154 corresponding to the coils can be increased in accordance with the coils, the objective lens 100 can be moved in the focus direction X.
Further, it is possible to drive with high sensitivity in two directions of the tracking direction Y.

In addition, in this embodiment, the focus coil 1
31 (132) has a focus magnet 151 (15
2) corresponds to the tracking coil 133 (134), and the tracking magnet 153 (154) corresponds to the tracking coil 133 (134). Therefore, different forces such as a magnetic field from the focus magnet 151 (152) and a magnetic field from the tracking magnet 153 (154) are applied. The generated magnetic fields do not interfere with each other.

Therefore, for example, when finely adjusting the objective lens 100 in the focus direction X, the focus coil 1
Even if an electric current is passed through 31 (132), the focus coil 131 (13) is moved from the tracking magnet 153 (154).
Since the magnetic field acting on 2) is extremely small, it is possible to prevent unwanted movement of the objective lens 100. On the other hand, in Prior Art 2, since the magnetic field of the magnet acting on the tracking coil acts on one surface of the focus coil, torque that rotates around the axis in the tangential direction Z is generated and the objective lens moves undesirably. .

Further, in this embodiment, the focus coil 1
31 (132) and tracking coil 133 (13
4) is made flat, the flat surface is fixed to the holder 110, and the focus coil 131 (132) and the tracking coil 133 (134) are respectively attached to the first attachment surfaces 111a and 111b and the second attachment surface 112.
Since it is installed parallel to a and 112b, holder 1
The rigidity of the focus coil 131 (132) and the tracking coil 133 (134) attached to the unit 10 is significantly increased, and the resonance frequency of the mode in which the coil itself is deformed is significantly increased. Further, the holder 110 itself has a rectangular block shape and high rigidity, and the central opening is reinforced by the objective lens 100 and the chromatic aberration correction lens 120, and the outer peripheral part is reinforced by the flat coil, so the rigidity is high, The resonance frequency also becomes high.

By the way, the magnetism generating means of this embodiment is
An open magnetic circuit having no yoke forming a magnetic gap, which is composed of focus magnets 151 and 152 and magnetic tracking magnets 153 and 154 that are magnetized in two poles, is configured. In this case, since it is not necessary to provide the holder 110 with an opening for disposing the yoke, the rigidity of the holder 110 can be increased by the rigidity of the opening.

Further, in this embodiment, the spring 1 is arranged so that the support member sandwiches the focus coils 131 and 132.
Since they are 40a and 140b, the width of the holder 110 in the tracking direction can be set smaller without increasing the width of the supporting member.

Furthermore, in the present embodiment, the base 141 is of a cylindrical shape, and since there is no inner yoke that directly faces the focus magnet and the tracking magnet, a cantilever-shaped yoke or the like is not required. The rigidity of 141 can be improved.

FIG. 5 is a perspective exploded view showing a recording / reproducing apparatus for an optical disc according to a second embodiment of the present invention.

Similar to the first embodiment, this recording / reproducing apparatus is a recording / reproducing apparatus for the optical disk 1 of the phase change recording system, and can drive the objective lens 100 in two directions of a focus direction X and a tracking direction Y orthogonal to each other. To support. Therefore, the same parts as those in the first embodiment are indicated by the same reference numerals and the description thereof will be omitted.

The holder 110 has two first mounting surfaces 111a and 111b opposed to the holder 110 in the tracking direction Y and two second mounting surfaces 112a opposed to the holder 110 in the tangential direction Z. , 112b.

The focus magnet 171 is bonded and fixed parallel to the first mounting surface 111a on the first mounting surface 111a, and the focus magnet 172 is parallel to the first mounting surface 111b on the first mounting surface 111b. It is glued and fixed to.

The tracking magnet 173 is bonded and fixed to the second mounting surface 112a in parallel with the second mounting surface 112a, and the tracking magnet 174 is also bonded to the second mounting surface 112a in the same manner.
It is adhesively fixed in parallel to 12b.

The base 141 is the focus magnet 1
71,172 and tracking magnets 173,1
In order to prevent 74 from being magnetically attracted, the focus coils 181 and 18 are made of non-magnetic stainless steel and are provided on the inner walls facing each other in the tracking direction Y, respectively.
2 is bonded in parallel to the inner wall in the tracking direction, while tracking coils 183 and 184 are bonded in parallel to the inner wall opposite to each other in the tangential direction Z.

In other words, in contrast to the first embodiment in which the coil is arranged in the holder 110 which is the movable portion, the present embodiment is a moving magnet in which the magnet is arranged in the holder 110. Therefore, according to the present embodiment, it is not necessary to supply power to the holder 110 that is the movable portion.

The first embodiment and the second embodiment can be used in combination, and by attaching the tracking coil and the focus magnet to the holder 110 and the focus magnet and the tracking coil to the base 141. Alternatively, either the focus direction X or the tracking direction Y may be driven by the moving coil, and the other may be driven by the moving magnet.

FIG. 6 is a perspective exploded view showing a recording / reproducing apparatus for an optical disc according to a third embodiment of the present invention.

Similar to the first embodiment, this recording / reproducing apparatus is also a recording / reproducing apparatus for an optical disk of the phase change recording system, and the objective lens 100 can be driven in two directions of a focus direction X and a tracking direction Y orthogonal to each other. It is something to support. Therefore, the same parts as those in the first embodiment are indicated by the same reference numerals and the description thereof will be omitted.

In this embodiment, an insulating layer made of polyimide having a thickness of about 5 (μ: micron) is provided on the surfaces of the springs 140a, 140b, and aluminum made of aluminum is formed on the insulating layer.
A wiring pattern of a book is formed.

In this embodiment, the four springs 140a, 1
Since there are 40b, the total wiring pattern is 8, but only 6 of them are actually used, and the breakdown is 2 for the tracking coils 133 and 134.
Two for each of the focus coils 131 and 132. As a result, the focus coils 131, 1
32 can be independently powered.

Here, the focus coils 131 and 132
When the focus servo current is supplied so as to generate the same force in the focus direction X, the objective lens 10
0 can be finely adjusted in the focus direction X. On the other hand, as shown in FIG. 6, when the tilt servo current is supplied to each of the focus coils 131 and 132 so as to generate the force in the opposite focus direction X, the rotation θz about the tangential axis Z is generated, and the objective lens is rotated. Since the lens 100 can be tilted around the tangential axis Z, coma and the like can be corrected. When a servo current obtained by adding the focus servo current and the tilt servo current is supplied to each of the focus coils 131 and 132, the objective lens 100 can be tilted about the tangential axis Z while finely adjusting the objective lens 100 in the focus direction X. This is more effective for correcting aberrations.

That is, in this embodiment, the focus coils 131 and 132 can control the direction of the current flowing through the coils.
The objective lens 100 can be tilted in the tracking direction Y if the directions in which power is supplied to 132 are opposite to each other.

Particularly in the present embodiment, the optical disc 1
The tilt servo can be applied around the tangential axis θz by using the tilt sensor or the track crosstalk signal of the reproduction signal. In this case, the objective lens 1
Since the coma aberration can be corrected by inclining 00, the aberration of the light spot is improved, and good recording / reproducing is possible.

Also in this embodiment, the first embodiment and the second embodiment can be used in combination, and either the focus direction X or the tracking direction Y is driven by the moving coil. The other may be driven by a moving magnet. In addition to the focus coils 131 and 132, the tracking coil 13
3, 134 or both the focus coils 131, 132 and the tracking coils 133, 134 may be capable of controlling the direction of the current flowing through the coils.

The above description merely shows the preferred embodiments of the present invention, and those skilled in the art can make various modifications within the scope of the claims. For example, the first
In the third embodiment, the central axis O _{1 of the} holder is set to the objective lens 100 so that the fine adjustment of the objective lens 100 is facilitated.
Although it is aligned with the optical axis of
There is no need to match ₁ to the optical axis of the objective lens 100.
Further, although the magnets having two poles are opposed to each other on the two sides of the focus coil and the tracking coil, the single pole magnet may be opposed to only one side.

Further, the first and the second provided on the holder 110.
Mounting surfaces 111a, 111b, 112a, 112b
Is not limited to the focus direction X or the tracking direction as long as the center axis O ₁ of the holder 110 is arranged so as to generate an equal force in the same direction on the two focus or tracking coils or the two focus or tracking magnets. It is not always necessary to dispose them in Y.

Therefore, in the present embodiment, the actuator of the objective lens used in the recording / reproducing apparatus for the optical disc is exemplified, but the optical element is not limited to the objective lens, but may be a collimator lens or an LD (laser diode). However, the device is also applicable to an actuator of a collimating lens for coupling with a fiber of an optical communication device.

[Brief description of drawings]

FIG. 1 is a perspective view showing a recording / reproducing apparatus for an optical disc according to a first embodiment of the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a sectional view showing FIG. 1 from the tangential direction.

FIG. 4 is an exploded perspective view of the same embodiment.

FIG. 5 is a perspective view showing a recording / reproducing apparatus for an optical disc according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a recording / reproducing device for an optical disc according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing an actuator of an optical element according to a conventional technique.

FIG. 8 is a perspective view showing an actuator of another optical element according to the related art.

[Explanation of symbols]

1 optical disc 100 objective lens 110 holder 111a, 111b First mounting surface 112a, 112b Second mounting surface 115 Fixed part 116 120 chromatic aberration correction lens 131,132 Focus coil 133,134 Tracking coil 140a, 140b springs 141 base 141f spherical surface 141g Base mounting surface 142 spring holder 142a, 142b Spring fixing part 151,152 Focus magnet 153,154 Tracking magnet 160 carriage 161 reflective mirror 162 sensor holder 163 PD (photo diode) 164 LED (light emitting diode) 171,172 Focus magnet 173,174 Tracking magnet 181,182 Focus coil 183,184 Tracking coil

Claims (9)

[Claims] 1. A first direction and a second direction orthogonal to the optical element.
In an actuator for an optical element that is drivably supported in two directions, a holder that holds the optical element, two first mounting surfaces and two second mounting surfaces that are provided in the holder so as to surround the central axis of the holder. A mounting surface, a first flat coil mounted parallel to the first mounting surface, a second flat coil mounted parallel to the second mounting surface, and the first and second flat coils An actuator for an optical element, comprising: a magnetic field generating unit that directs a magnetic field to the substrate; and a support member that supports the holder so as to be drivable in a first direction and a second direction. 2. A first direction and a second direction orthogonal to the optical element.
In an actuator for an optical element that is drivably supported in two directions, a holder that holds the optical element, two first mounting surfaces that are arranged to face the holder in the second direction, and the first and second Two second mounting surfaces arranged to face the holder in a third direction orthogonal to the first direction;
A first flat coil mounted parallel to the mounting surface, a second flat coil mounted parallel to the second mounting surface, and a magnetic field for directing a magnetic field to the first and second flat coils Means and first said holder
And a support member that is drivably supported in the second direction and the second direction. 3. The actuator for an optical element according to claim 1, wherein the magnetic field generating means is a magnet having a two-pole magnetization. 4. The first flat coil generates a driving force in a first direction, and the second flat coil is a second flat coil.
The actuator of the optical element according to claim 2 or 3, which generates a driving force in a direction. 5. The actuator for an optical element according to claim 1, wherein the magnetic field generating means is an open magnetic circuit having no yoke forming a magnetic gap. 6. The actuator of the optical element according to claim 2, wherein the support member holds the first flat coil. 7. The actuator for an optical element according to claim 2, wherein the first direction is a direction parallel to the optical axis of the optical element. 8. The coil according to claim 2, wherein at least one coil of the first flat coil and the first flat coil is capable of controlling a direction of a current flowing through the coil. An actuator of the optical element according to any one of items. 9. A first direction and a second direction orthogonal to the optical element.
In an actuator for an optical element that is drivably supported in two directions, a holder that holds the optical element, two first mounting surfaces that are arranged to face the holder in the second direction, and the first and second Two second mounting surfaces arranged to face the holder in a third direction orthogonal to the first direction;
A first magnet mounted parallel to the mounting surface,
A second mounted parallel to the second mounting surface
An actuator for an optical element, comprising a magnet, a coil arranged to face the first and second magnets, and a support member that supports the holder so as to be drivable in the first direction and the second direction. .